Change the jumpers so one is master and the other slave. Chain them on the same ribbon. If you have no clue what any of that means, hire someone to do it.
Inside each person lives two wolves. One is loyal, kind, respectful, humble and open to the mystery of life. The other is greedy, jealous, hateful, afraid and blind to the wonders of life. They are in battle for your spirit. The one who wins is the one you feed.
It should have come with the manual. Setting up another hard drive is pretty easy. Follow the manual if it came with one, make sure your jumper settings are correct.